Topeka ? Kansas Attorney General Stephen Six will make his first appearance before the U.S. Supreme Court on Monday, the latest legal move in the lengthy dispute between Kansas and Colorado over use of the Arkansas River.

Six, who has served as attorney general for less than a year, will try to persuade the Supreme Court justices to overturn earlier court rulings that limited how much Colorado has to pay Kansas for infractions of a water-rights agreement.

Kansas and Colorado signed the compact in 1949 after legal disagreements regarding the Arkansas River. Colorado’s subsequent development of 2,000 high-capacity wells near the river reduced the water available to Kansans. The dispute is about Colorado’s use of water from the river between 1950 and 1996.

In 1985, Kansas sued Colorado for violating a water-rights agreement tied to the Arkansas River. The Supreme Court ruled a decade later that Colorado violated some provisions of the contract and awarded Kansas $34.6 million in damages.

A special master, appointed by justices to hear the case, later limited payment of interest on the damages and also denied Kansas reimbursement for the cost of developing computer models used in the case.

Six is arguing Monday that the Supreme Court should overturn those rulings from the special master. He will contend that federal rules limiting reimbursements shouldn’t apply to this case.

Six says the reimbursement limits shouldn’t apply because Kansas v. Colorado is part of the Supreme Court’s “original jurisdiction,” meaning it is in a category of cases that follow a different track than typical appellate actions.

The computer models used by Kansas to prove Colorado violated the river agreement cost Kansas millions of dollars.

“Colorado violated the Arkansas River Compact for almost 50 years,” Six said. “It is only fair that Kansas be reimbursed a reasonable and fair amount for its costs in proving Colorado’s violations.”

The special master determined that the only expert witness costs Colorado would be required to reimburse Kansas for was a $40-a-day witness appearance fee. Six will counter that the Constitution doesn’t allow Congress to impose limits on the Supreme Court’s handling of rare original action cases.